[PATCH 1/2] powerpc: document the MPIC device tree binding
meador_inge at mentor.com
Thu Jan 20 11:08:03 EST 2011
On 01/19/2011 04:14 PM, Yoder Stuart-B08248 wrote:
>> +** Optional properties:
>> + - no-reset : The presence of this property indicates that the MPIC
>> + should not be reset during runtime initialization.
>> + - protected-sources : Specifies a list of interrupt sources that are
>> + not
>> + available for use and whose corresponding
>> + vectors
>> + should not be initialized. A typical use case
>> + for
>> + this property is in AMP systems where multiple
>> + independent operating systems need to share
>> + the MPIC
>> + without clobbering each other.
> Is "protected-sources" really needed for AMP systems to
> tell the OSes not to clobber each other? Won't each
> OS be given a device tree with only its interrupt
> sources? ...so you know what you are allowed to touch.
This was discussed a little bit already [1, 2]. The MPIC driver
currently initializes the VECPRI register for all interrupt sources,
which can lead to the aforementioned clobbering.
Meador Inge | meador_inge AT mentor.com
Mentor Embedded | http://www.mentor.com/embedded-software
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